Due to the progress and development in different industrial fields, the high productivity brought by the mechanized and automated production, as well as various highly matured technological skills, many daily necessaries are now mainly produced with low-cost chemical compounds and plastic materials to enable high output and low price thereof. However, the use of a large quantity of products made of chemical compounds and plastic materials inevitably results in many environmental problems, such as air pollution and water contamination.
Meanwhile, following the constantly upgraded living standards, people pay more attention to the quality of their drinking water. There are now various kinds of water filters developed and introduced into the market. All these water filters internally include a filter cartridge received in a filter cylinder. The water filter removes impurities from water, so that a user can obtain clean drinking water. However, most of the commercially available filter cylinders involve complicated procedures to disassemble and re-assemble them, and the filter cartridges in the filter cylinder could not be easily replaced by general users.
There are also different kinds of water filter jugs available in the market. A general water filter jug includes a container internally provided with a filter cartridge or a filter cylinder for holding water to be filtered. When the unfiltered water poured into the container seeps through the filter cartridge or the filter cylinder due to gravity, impurities and bacteria are filtered from the water. Most water filter jugs are not designed for personal use; they have a large volume and could not be easily carried about for use outdoors in a convenient manner.
Since the currently available water filter jugs could not be conveniently carried about for use in ocean activities or mountain activities in isolated areas, it is uneasy to get clean drinking water at any time in case of an emergency during an ocean or mountain activity, and it is dangerous to directly drink surface water or seawater. Particularly, in view of many natural calamities possibly caused by the increasingly serious problem of global warming in recent years, it becomes very important for people to have means usable in all kinds of emergencies or disasters to quickly and conveniently get drinkable water to survive in the disaster and wait for rescue. In brief, an uninterrupted source of drinkable water forms the most important factor to survive in an emergency or disaster.
Therefore, portable water filtering devices have been researched and developed. Please refer to FIGS. 1A, 1B and 1C. A conventional water filtering device 1 mainly includes an outer bag 11 and an inner filter bag 12. The outer bag 11 internally defines a receiving space 111 and has two conduits 112 spaced on a bottom thereof. A top of the outer bag 11 forms a zip-lock opening 113. The conduits 112 can be connected to the outer bag 11 in a watertight manner by means of ultrasonic welding or gluing. The filter bag 12 is mainly used to separate ions from water. It internally defines a filtering space 121 and has a top forming a zip-lock opening 122. To use the water filtering device 1, first put the filter bag 12 in the receiving space 111 of the outer bag 11 with a bottom of the filter bag 12 abutted against the conduits 112, and then pour unfiltered water into the filtering space 121 of the filter bag 12. The outer bag 11 and the filter bag 12 received therein are then sealed at their zip-lock openings and squeezed, as shown in FIG. 3C, so that the unfiltered water in the filter bag 12 seeps through the filter bag 12 into a space between the outer bag 11 and the filter bag 12 to flow out of the outer bag 11 via the conduits 112. The water is filtered when it seeps through the filter bag 12.
The outer bag 11 and the filter bag 12 for the conventional water filtering device 1 are separated from each other before they are used outdoors. It is inconvenient for a user to carry two separate bags 11, 12 and to further assemble the two bags 11, 12 together for use. It is also troublesome to squeeze the assembled outer bag 11 and filter bag 12 to achieve the purpose of filtering water. Further, the conventional water filtering device 1 can only filter water one time via the filter bag 12 and fails to effectively filter impurities and bacteria from water. The water filtering device 1 does not include any structure for effectively storing the filtered water; and the zip-lock openings 113, 122 of the outer bag 11 and the filter bag 12, respectively, could not be securely sealed and tend to be opened under squeezing. As a result, unfiltered water in the filter bag 12 tends to overflow the zip-lock opening 122 to contaminate the filtered water in the receiving space 111 of the outer bag 11.
In conclusion, the above-structured conventional water filtering device 1 has the following disadvantages: (1) it is not conveniently portable and requires further assembling procedures; (2) it must be squeezed to achieve the purpose of filtering water, and the single-layer filter bag fails to simultaneously filter impurities and bacteria from water; (3) it can not effectively store the filtered water; and (5) the filtered water is easily contaminated by the unfiltered water overflowed the zip-lock opening of the filter bag.
It is therefore tried by the inventor to develop an improved water filtering device to eliminate the disadvantages in the conventional water filtering device.